The air conditioning systems on some 2005-06 Ford 4.6L Mustangs may blow warm air. If the system has a full charge, no fuses are blown and the compressor clutch won’t engage, chances are the clutch has fried, says Ford. Installing a new clutch assembly and updated orifice tube and recharging the system to a new refrigerant spec of 26 oz. should bring back the cool. After you’re done with the parts swap, fill out a climate control information decal and place it underhood to alert the next tech that works on the vehicle.